I have the TP-PA7010P starter kit. It does not have wi-fi built-in.

https://www.tp-link.com/es/home-networking/powerline/tl-pa7010p-kit/

I want to add another tp-link adapter, but this new one must have ethernet *and* wifi.

My local shop has TL-WPA4221 Kit (AV600 - N300)

https://www.tp-link.com/es/home-networking/powerline/tl-wpa4221-kit/

I don't want to use the large white AV600 adapter, which plugs into the router. I already have the AV1000 adapter plugged into my router.

I just need to use the small, grey one to pair with the existing AV1000 adapter, and provide an ethernet signal to a desktop, and a wi-fi signal to that room.

Can anyone confirm that these devices are compatible, and that I can pair the small, grey AV600 adapter with the existing AV1000 network, without using the bigger, white AV600 adapter plugged into my router? And that this set-up would give me wi-fi in that room?

Also, my existing AV1000 would still be gigabit speed, right? Joining the AV600 adapter wouldn't slow everything down, would it?

Thanks.